Siege

siege, assault against a city or fortress with the purpose of capturing it. The history of siegecraft parallels the development of
fortification and, later,
artillery. In early times battering rams and bores were employed to break down the walls and gates of a fortified place (see
castle) if deception, treachery, starvation, or storm could not carry it. To protect the attackers from missiles, hot oil, and incendiaries launched
by the defenders, a shelter was constructed, usually from huge wicker shields covered with wood or hide (mantelets). Mounds and movable wooden towers
were built by both besieger and besieged in a race to attain heights from which the adversary could be assailed. Engines of war, such as the
catapult, were brought into play by both sides to hurl stones, spears, pots of fire, and arrows. It was also common for besiegers to build a wall
(circumvallation) around their objective to prevent sorties and a second wall (contravallation) around their own army as security against relieving
forces. Mining was employed by the assailants from earliest times, and the besieged dug countermines in defense; such tactics greatly increased in
effectiveness with the introduction of gunpowder. Artillery that could breach high walls made it necessary to lower and extend medieval fortifications
and mount defensive artillery. Many sieges became artillery duels. The development of tanks, aircraft, and missiles in the 20th cent. has given the
besieger a great advantage in firepower and mobility. Some notable sieges of history include those of Syracuse (415–413 B.C.),
Jerusalem (A.D. 70), Acre (1189–90), Constantinople (1453), Quebec (1759–60), Sevastopol (1854–55, 1941–42),
Vicksburg (1863), Port Arthur (1904), Malta (1940–43), Leningrad (1941–43), Dienbienphu (1954) and Khe Sanh (1968).
-Answers.com

Siege warfare is the third member of the strategies of medieval warfare, the other two being the raid and the pitched battle. Where as the pitched
battle was extremely rare and the raid very common; the siege fell in between the two. After all, it was the town and fortified positions such as keeps
and castles that provided the true military power within any region just by it presence and the fact that they housed men-at-arms who could sortie out
and attack any force moving through their lands. Therefore, if a commander wished to gain control of a region he would have to invest any and all
fortified positions within it to gain that control.

As I stated on the home page I will base my descriptions of medieval tactics on those of medieval Europe between 1066 and 1250.

To assist the reader in seeing how I came up with my descriptions and conclusions I have included the historical references I relied on; however, since
the Hârnic material is very sparse on tactics I have not reference anything from these sources.